Prior art refrigeration units for use with cabinet or countertop food preparation are well known in the art. Typical patents include U.S. Pat. No. 5,363,672 issued on Nov. 15, 1994, U.S. Pat. No. 5,388,429 issued on Feb. 14, 1995, U.S. Pat. No. 5,355,687 issued on Oct. 18, 1994, U.S. Pat. No. 5,277,039 issued on Jan. 11, 1994, and U.S. Pat. No. 5,381,672 issued on Jan. 17, 1995. However, problems associated with food preparation refrigeration units continue to exist. Such problems include failing to adequately cool all the regions of the food contained in the food pans. Several patents disclose food pan arrangements with cooling coils in the units and cold air circulation around open top food pans.
Since the top portion of food in an open top food pan is exposed to the ambient air temperature and typically is furthest from the cooling zones, this portion of the food is more susceptible to spoiling. Prior patents addressing this problem often used evaporators in close proximity to the food pans and often added an upper cooling zone. Some prior patents attempted to cool the top portion of food in the pans by blowing cold air directly across the food in a standard compression refrigeration system. However, prior refrigeration units for use in countertop food preparation do not adequately cool the top portion of the food without drying it or causing frost to accumulate near the upper edges of the refrigeration unit.
Accordingly, it is an object of the present invention to provide a countertop food preparation refrigeration unit which provides additional cooling to the top layer of food in the food pan to prevent this food from spoiling due to exposure to the ambient air temperature. Additional objects of the invention are to prevent frost from accumulating on the outside rim near the food pans and to avoid drying out the food. Thus, an overall object of the present invention is to provide a simple and economical refrigeration unit for a countertop food preparation assembly embodying these features.